Are you talking third party adverts from Asda and McDonald’s etc with on demand content?
Or promo trailers for Sky/NOW content?
If it’s the latter then they are NOT classed as adverts and sorry to say won’t be going anywhere anytime soon.
If it’s the former, you need to log out and log back in as adding boost can take up to four hours.
FYI that I do not work for NOW, just a NOW customer trying to help